Located in the Bristol Tower condominium in Miami’s Brickell neighborhood, the apartment includes a circular living room

Musician and producer Pharrell Williams’s Miami penthouse—which has a Venetian Plaster spiral staircase leading to a translucent dome—has sold for $9.25 million after several years on and off the market.

Mr. Williams bought the triplex in 2007 for $12.525 million, according to public records. He first put it on the market in 2012 for $16.8 million with another firm. It saw several price reductions before real-estate agent Dora Puig of Luxe Living Realty took over the listing in 2014, pricing it at $10.999 million. She said he took it off the market for much of 2015 while the building was undergoing renovations, then relisted it this winter.

The “Happy” singer-songwriter, 43, is selling because his primary home is now Los Angeles, where he is a coach on NBC’s music reality show “The Voice,” Ms. Puig said. He couldn’t be reached for comment.

The spiral staircase leads from the second level, which holds a billiards room and a gym, to a mezzanine under the dome. The apartment also has three levels of decks and terraces, including a private outdoor pool and a barbecue area.

The buyer was represented by Julian Johnston of Calibre International Realty. Mr. Johnston declined to identify the purchaser but said he is a businessman from New Jersey who is relocating to Florida and will use the penthouse as his primary home.